21705520410 has 96 divisors (see below), whose sum is σ = 64592940672. Its totient is φ = 4953836160.

The previous prime is 21705520357. The next prime is 21705520451. The reversal of 21705520410 is 1402550712.

21705520410 is a `hidden beast` number, since 2 + 1 + 70 + 552 + 0 + 41 + 0 = 666.

It is a super-2 number, since 2×21705520410² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 401065 + ... + 451955.

It is an arithmetic number, because the mean of its divisors is an integer number (672843132).

Almost surely, 2^21705520410 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21705520410, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32296470336).

21705520410 is an abundant number, since it is smaller than the sum of its proper divisors (42887420262).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21705520410 is a wasteful number, since it uses less digits than its factorization.

21705520410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51588 (or 51585 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The spelling of 21705520410 in words is "twenty-one billion, seven hundred five million, five hundred twenty thousand, four hundred ten".